function ReaderError(message){
    this.message = message  || '默认输出信息'
     this.name = 'ReadeError'
    this.stack = (new Error()).stack
}

ReaderError.prototype = Object.create(Error.prototype)
ReaderError.prototype.constructor = ReaderError;

try{
    throw new EvalError("读取错误")
}catch(e){
  if(e instanceof ReaderError){   //e是ReaderError的实例
    console.log(JSON.stringify(e))
  }else if(e instanceof EvalError){
    console.log("EvalError")
  }
}
